DOCSLIB.ORG

The Icelandic Laki Volcanic Tephra Layer in the Lomonosovfonna Ice Core, Svalbard

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
The Icelandic Laki Volcanic Tephra Layer in the Lomonosovfonna Ice Core, Svalbard The Icelandic Laki volcanic tephra layer in the Lomonosovfonna ice core, Svalbard Teija Kekonen, John Moore, Paavo Perämäki & Tõnu Martma The largest sulphuric acid event revealed in an ice core from the Lomono- sovfonna ice cap, Svalbard, is associated with the densest concentration of microparticles in the ice core at 66.99 m depth. Electron microscope analysis of a volcanic ash particle shows it has the same chemical compo- sition as reported for debris from the eruption of Iceland’s Laki fi ssure in 1783 and confi rms the identifi cation of the tephra. Most of the particles in the deposit are not ash, but are common sand particles carried aloft during the eruption event and deposited relatively nearby and downwind of the long-lasting eruption. The tephra layer was found 10 - 20 cm deeper than high sulphate concentrations, so it can be inferred that tephra arrived to Lomonosovfonna about 6 - 12 months earlier than gaseous sulphuric acid precipitation. The sulphuric acid spike has a signifi cant cooling impact recorded in the oxygen isotope profi le from the core, which corresponds to a sudden drop in temperature of about 2 °C which took several years to recover to previous levels. These data are the fi rst particle analyses of Laki tephra from Svalbard and confi rm the identifi cation of the large acidic signal seen in other ice cores from the region. They also confi rm the very large impact that this Icelandic eruption, specifi cally the sulphu- ric acid rather than ash, had on regional temperatures. T. Kekonen, University of Oulu, Box 3000, FI-90014 University of Oulu, Finland and Arctic Centre, Uni- versity of Lapland, Box 122, FI-96101 Rovaniemi, Finland, teija.kekonen@oulu.fi ; J. Moore, Arctic Centre, University of Lapland, Box 122, FI-96101 Rovaniemi, Finland; P. Perämäki, Dept. of Chemistry, University of Oulu, Box 3000, FI-90014 University of Oulu, Finland; T. Martma, Institute of Geology, Tallinn Univer- sity of Technology, Estonia pst 7, EE-10143 Tallinn, Estonia. Volcanic ash particles are commonly detect- particle size. In addition to volcanic ash particles, ed from ice cores because of their importance tephra contains other larger sand and rock par- for dating (e.g. Grönvold et al. 1995; Zielinski ticles. Ash and other small particles can travel et al. 1997). Volcanic eruptions usually produce long distances, but bigger sand particles are much large volumes of SO2 gas, dust, lava, ash and rock heavier than ash and are deposited much closer (Thordarson et al. 2001). Volcanic material can to the eruption site. Volcanic ash is the smallest travel high into the atmosphere and mix with air tephra fragment (< 2 mm) composed of silicon, masses, which can spread very widely. This mate- aluminium, iron, calcium, magnesium, sodium rial is eventually scavenged in precipitation, or and other trace elements. Each volcanic eruption deposited dry in very arid regions. produces volcanic ash particles with a specifi c Volcanic tephra includes all rock and lava par- signature in these elements, thereby producing a ticles that are erupted into the air, regardless of chemical fi ngerprint by which it can be identifi ed Kekonen et al. 2005: Polar Research 24(1–2), 33–40 33 al. 1994; Zielinski et al. 1994; Thordarson et al. 1996; Watanabe et al. 2001; Thordarson & Self 2003). In this work we have analysed samples close to a major sulphate peak in the ice core and found a particle-rich layer at a depth of 66.99 m using SEM-EDS. This is the fi rst published result relat- ing to the tephra layer and volcanic ash particle from the Laki eruption located in Svalbard gla- ciers. Study site and methods The 121 m long ice core was recovered with an electromechanical drill from the summit of the Lomonosovfonna ice cap (1255 m a.s.l.), on the island of Spitsbergen, Svalbard, in 1997 (Fig. 1) (Isaksson et al. 2001). Total ice depth from radar sounding was 123 m, and the site is close to the highest point of the ice cap with roughly radial ice fl ow. The ice core represents an approximate- ly 800 year period. The time scale of the core was based on an ice layer thinning model (Nye 1963) tied with the known dates of prominent reference horizons (1963 radioactive layer and 1783 Laki Fig 1. Map showing Svalbard and Iceland and the inferred volcanic sulphate layer and volcanic ash particle; plume direction of the westerly jet stream on 10 June 1783. Transport paths are based on the data of Thordarson & Self see Kekonen et al. [2005] for details). The accu- (2003) and Fiacco et al. (1994). mulation rate for the 1997–1963 period is 0.41 m water equivalent per year and a somewhat lower value of 0.31 m w.e. per year for the period 1963– (e.g. Palais et al. 1992; Grönvold et al. 1995; Zie- 1783. The model age profi le can be independently linski et al. 1997; Zielinski et al. 1998). checked by comparison with automated seasonal The eruption of Iceland’s Laki fracture in 1783 cycle counting in stable isotopes and ions down to was one of largest basaltic fi ssure eruptions in 81 m (Pohjola et al. 2002). The model age at 81 m recorded history. The volume of aerosols inject- depth is 1705, while the cycle counting method ed into the atmosphere by the eruption was one gives a date of 1715. There is a thus a discrepan- of the greatest atmospheric pollution events over cy of 10 years in about 75 years between the Laki Europe during historic times (Thordarson & Self horizon and the limit of cycle counting. Howev- 2003). The Laki volcanic eruption lasted for eight er, the cycle counting method will always tend to months (June 1783 to February 1784) and pro- miss a fraction of low accumulation rate years duced one of the largest recorded basaltic lava due to the resolution of the data and isotope dif- fl ows in Iceland. The sulphuric and, especially, fusion effects, so a good model dating should be the hydrofl uoric acid produced by the eruption more reliable (on average) than cycle counting. were responsible for the deaths of more than half The current annual temperature range is from the animals on Iceland (Thordarson & Hoskulds- 0 °C to about –40 °C. Any summer meltwater son 2002). There were also widespread effects is refrozen mostly within the previous winter’s in the Northern Hemisphere, including cooling snow, and the remainder within the next two or (Thordarson & Hoskuldsson 2002; Highwood & three lower annual layers. Although percolation Stevenson 2003; Thordarson & Self 2003). can be up to eight years in the warmest years in A strong sulphate acid signal corresponding the 20th century, it was much reduced during to an age of 1783–84 has been reported in many the Little Ice Age (Kekonen et al. 2005). Vari- ice cores from Greenland and Svalbard (Fiacco et ous statistical analytical methods (see Kekonen 34 The Laki tephra layer in the Lomonosovfonna ice core et al. 2005; Moore et al. 2005) show that chemi- measure the chemical composition of all the par- cal and isotopic stratigraphy are suffi ciently well ticles present on a 271 × 191 mm subsections of preserved that signifi cant decadal-scale periodic- the 490 mm2 fi lter membrane. In total we ana- ities can be found, annual layers can be count- lysed 2063 particles in 44 different subsections of ed for about 300 years, and changes in chemical the same fi lter membrane. composition related to changes in climate are far more signifi cant than changes in chemical com- position in ice layers subject to various degrees Results and discussion of percolation. The core was transported and stored in a frozen There are no visible dust or tephra bands in the state (–22 °C). The whole ice core was cut into ice core, but particles were sought at many depths 5 cm sections and the outer parts of the samples using the method described above. Enormous were removed in a cold room under a laminar amounts of tephra (approximately half a mil- fl ow hood. For particle analyses, selected sam- lion particles) were detected on the 66.99 - 67.04 ples were melted and fi ltered under a laminar fl ow m depth fi lter membrane. The subsection typical- hood. The 10 - 20 ml of meltwater was fi ltered ly contained 30 - 100 particles, most commonly just after melting with Nuclepore polycarbonate 50. (For comparison, at other depths a subsection membranes (25 mm diameter and 0.2 mm pore usually contained less than 10 particles.) This is size) using a vacuum fi lter system. Each sample the only depth where tephra were found close to was fi ltered through separate fi lter membranes. a high sulphate and acidity peak (66.69 - 66.89 m) Filter membranes were glued onto the stubs using (Fig. 2). Most of the tephra were small sand par- carbon-coated double-sided tape and coated with ticles of basaltic composition (Fig. 3). The SiO2 a thin fi lm of carbon. Samples were analysed for composition is approximately same as in parti- major elements using a Jeol JMS-6400 scanning cles originating from Laki eruption as reported electron microscope combined with a Link ISIS in the literature (see references in Table 1). While and INCA energy dispersive spectrometer. An the automated analyses in Fig. 3 do not give very acceleration voltage of 15 kV and a beam current exact chemical compositions due to the nature of 1.2 nA were used for the SEM-EDS (scanning of the particle morphology, the large numbers of electron microscope energy dispersive spectrom- analyses give a statistical view of tephra com- eter) analysis with the sample distance of 15 mm.
Load more

Recommended publications
  • A Detection of Milankovitch Frequencies in Global Volcanic Activity
    A detection of Milankovitch frequencies in global volcanic activity Steffen Kutterolf1*, Marion Jegen1, Jerry X. Mitrovica2, Tom Kwasnitschka1, Armin Freundt1, and Peter J. Huybers2 1Collaborative Research Center (SFB) 574, GEOMAR, Wischhofstrasse 1-3, 24148 Kiel, Germany 2Department of Earth & Planetary Sciences, Harvard University, Cambridge, Massachusetts 02138, USA ABSTRACT 490 k.y. in the Central American Volcanic Arc A rigorous detection of Milankovitch periodicities in volcanic output across the Pleistocene- (CAVA; Fig. 1). We augment these data with Holocene ice age has remained elusive. We report on a spectral analysis of a large number of 42 tephra layers extending over ~1 m.y. found well-preserved ash plume deposits recorded in marine sediments along the Pacifi c Ring of in Deep Sea Drilling Project (DSDP) and Fire. Our analysis yields a statistically signifi cant detection of a spectral peak at the obliquity Ocean Drilling Program (ODP) Legs offshore period. We propose that this variability in volcanic activity results from crustal stress changes of Central America. The marine tephra records associated with ice age mass redistribution. In particular, increased volcanism lags behind in Central America are dated using estimated the highest rate of increasing eustatic sea level (decreasing global ice volume) by 4.0 ± 3.6 k.y. sedimentation rates and/or through correlation and correlates with numerical predictions of stress changes at volcanically active sites. These with radiometrically dated on-land deposits results support the presence of a causal link between variations in ice age climate, continental (e.g., Kutterolf et al., 2008; also see the GSA stress fi eld, and volcanism.
    [Show full text]
  • Extending the Late Holocene White River Ash Distribution, Northwestern Canada STEPHEN D
    ARCTIC VOL. 54, NO. 2 (JUNE 2001) P. 157– 161 Extending the Late Holocene White River Ash Distribution, Northwestern Canada STEPHEN D. ROBINSON1 (Received 30 May 2000; accepted in revised form 25 September 2000) ABSTRACT. Peatlands are a particularly good medium for trapping and preserving tephra, as their surfaces are wet and well vegetated. The extent of tephra-depositing events can often be greatly expanded through the observation of ash in peatlands. This paper uses the presence of the White River tephra layer (1200 B.P.) in peatlands to extend the known distribution of this late Holocene tephra into the Mackenzie Valley, northwestern Canada. The ash has been noted almost to the western shore of Great Slave Lake, over 1300 km from the source in southeastern Alaska. This new distribution covers approximately 540000 km2 with a tephra volume of 27 km3. The short time span and constrained timing of volcanic ash deposition, combined with unique physical and chemical parameters, make tephra layers ideal for use as chronostratigraphic markers. Key words: chronostratigraphy, Mackenzie Valley, peatlands, White River ash RÉSUMÉ. Les tourbières constituent un milieu particulièrement approprié au piégeage et à la conservation de téphra, en raison de l’humidité et de l’abondance de végétation qui règnent en surface. L’observation des cendres contenues dans les tourbières permet souvent d’élargir notablement les limites spatiales connues des épisodes de dépôts de téphra. Cet article recourt à la présence de la couche de téphra de la rivière White (1200 BP) dans les tourbières pour agrandir la distribution connue de ce téphra datant de l’Holocène supérieur dans la vallée du Mackenzie, située dans le Nord-Ouest canadien.
    [Show full text]
  • Disaster Aid After the 1783 Laki Eruption
    Preprints (www.preprints.org) | NOT PEER-REVIEWED | Posted: 25 June 2020 doi:10.20944/preprints202001.0070.v2 Haze, Hunger, Hesitation: Disaster aid after the 1783 Laki eruption Claudia E. Wieners ∗ aInstitute of Economics, Scuola Superiore Sant’Anna, Pisa, Italy bCentre for Complex Systems Studies, Utrecht University, Netherlands Abstract The 1783-1784 Laki eruption was one of the most severe natural catastrophes to occur in Iceland in historical times (since 1140 years). Vegetation damage by sulphate aerosol and fluorine poisoning caused a massive decimation of live- stock. The impact of fluorine poisoning and sulphate aerosol on human mortal- ity is uncertain, but the loss of animals caused a famine which took many lives. The vulnerability of the Icelandic society to famine is discussed. 18th Century Iceland was a Danish dependency and, despite the abundance of fish in the surrounding waters, a subsistence farming community and thus highly depen- dent on livestock. On the other hand, the farming community possessed coping strategies which mitigated the impact of livestock loss. During the famine, the Danish government was in principle willing to provide relief. However, local authorities in Iceland were slow to ask for help, and did not dare to exploit the means at their disposal (e.g. the right to ban the export of Icelandic foodstuff) without consent from Copenhagen. The Danish officials in turn were unwill- ing to act decisively upon incomplete information. These two factors prevented timely measures. While 4:4 × 105kg of grain were provided for famine relief in summer 1784, the merchants exported 1:2 × 106kg of fish, which greatly aggra- vated the hunger in the second winter.
    [Show full text]
  • Explosive Eruptions
    Explosive Eruptions -What are considered explosive eruptions? Fire Fountains, Splatter, Eruption Columns, Pyroclastic Flows. Tephra – Any fragment of volcanic rock emitted during an eruption. Ash/Dust (Small) – Small particles of volcanic glass. Lapilli/Cinders (Medium) – Medium sized rocks formed from solidified lava. – Basaltic Cinders (Reticulite(rare) + Scoria) – Volcanic Glass that solidified around gas bubbles. – Accretionary Lapilli – Balls of ash – Intermediate/Felsic Cinders (Pumice) – Low density solidified ‘froth’, floats on water. Blocks (large) – Pre-existing rock blown apart by eruption. Bombs (large) – Solidified in air, before hitting ground Fire Fountaining – Gas-rich lava splatters, and then flows down slope. – Produces Cinder Cones + Splatter Cones – Cinder Cone – Often composed of scoria, and horseshoe shaped. – Splatter Cone – Lava less gassy, shape reflects that formed by splatter. Hydrovolcanic – Erupting underwater (Ocean or Ground) near the surface, causes violent eruption. Marr – Depression caused by steam eruption with little magma material. Tuff Ring – Type of Marr with tephra around depression. Intermediate Magmas/Lavas Stratovolcanoes/Composite Cone – 1-3 eruption types (A single eruption may include any or all 3) 1. Eruption Column – Ash cloud rises into the atmosphere. 2. Pyroclastic Flows Direct Blast + Landsides Ash Cloud – Once it reaches neutral buoyancy level, characteristic ‘umbrella cap’ forms, & debris fall. Larger ash is deposited closer to the volcano, fine particles are carried further. Pyroclastic Flow – Mixture of hot gas and ash to dense to rise (moves very quickly). – Dense flows restricted to valley bottoms, less dense flows may rise over ridges. Steam Eruptions – Small (relative) steam eruptions may occur up to a year before major eruption event. .
    [Show full text]
  • 1783-84 Laki Eruption, Iceland
    1783-84 Laki eruption, Iceland Eruption History and Atmospheric Effects Thor Thordarson Faculty of Earth sciences, University of Iceland 12/8/2017 1 Atmospheric Effects of the 1783-84 Laki Eruption in Iceland Outline . Volcano-Climate interactions - background Laki eruption . Eruption history . Sulfur release and aerosol loading . Plume transport and aerosol dispersal . Environmental and climatic effects 12/8/2017. Concluding Remarks 2 Santorini, 1628 BC Tambora, 1815 Etna, 44 BC Lakagígar, 1783 Toba, 71,000 BP Famous Volcanic Eruptions Krakatau, 1883 Pinatubo, 1991 El Chichón, 1982 Agung, 1963 St. Helens, 1980 Major volcanic eruptions of the past 250 years Volcano Year VEI d.v.i/Emax IVI Lakagígar [Laki craters], Iceland 1783 4 2300 0.19 Unknown (El Chichón?) 1809 0.20 Tambora, Sumbawa, Indonesia 1815 7 3000 0.50 Cosiguina, Nicaragua 1835 5 4000 0.11 Askja, Iceland 1875 5 1000 0.01* Krakatau, Indonesia 1883 6 1000 0.12 Okataina [Tarawera], North Island, NZ 1886 5 800 0.04 Santa Maria, Guatemala 1902 6 600 0.05 Ksudach, Kamchatka, Russia 1907 5 500 0.02 Novarupta [Katmai], Alaska, US 1912 6 500 0.15 Agung, Bali, Indonesia 1963 4 800 0.06 Mt. St. Helens, Washington, US 1980 5 500 0.00 El Chichón, Chiapas, Mexico 1982 5 800 0.06 Mt. Pinatubo, Luzon, Philippines 1991 6 1000 — Volcano – Climate Interactions Key to Volcanic Forcing is: SO2 mass loading, eruption duration plume height replenishment aerosol production, residence time 12/8/2017 5 Volcanic Forcing: sulfur dioxide sulfate aerosols SO2 75%H2SO4+ 25%H2O clear sky 1991 Pinatubo aerosols
    [Show full text]
  • Canadian Volcanoes, Based on Recent Seismic Activity; There Are Over 200 Geological Young Volcanic Centres
    Volcanoes of Canada 1 V4 C.J. Hickson and M. Ulmi, Jan. 3, 2006 • Global Volcanism and Plate tectonics Where do volcanoes occur? Driving forces • Volcano chemistry and eruption types • Volcanic Hazards Pyroclastic flows and surges Lava flows Ash fall (tephra) Lahars/Debris Flows Debris Avalanches Volcanic Gases • Anatomy of an Eruption – Mt. St. Helens • Volcanoes of Canada Stikine volcanic belt Presentation Outline Anahim volcanic belt Wells Gray – Clearwater volcanic field 2 Garibaldi volcanic belt • USA volcanoes – Cascade Magmatic Arc V4 Volcanoes in Our Backyard Global Volcanism and Plate tectonics In Canada, British Columbia and Yukon are the host to a vast wealth of volcanic 3 landforms. V4 How many active volcanoes are there on Earth? • Erupting now about 20 • Each year 50-70 • Each decade about 160 • Historical eruptions about 550 Global Volcanism and Plate tectonics • Holocene eruptions (last 10,000 years) about 1500 Although none of Canada’s volcanoes are erupting now, they have been active as recently as a couple of 4 hundred years ago. V4 The Earth’s Beginning Global Volcanism and Plate tectonics 5 V4 The Earth’s Beginning These global forces have created, mountain Global Volcanism and Plate tectonics ranges, continents and oceans. 6 V4 continental crust ic ocean crust mantle Where do volcanoes occur? Global Volcanism and Plate tectonics 7 V4 Driving Forces: Moving Plates Global Volcanism and Plate tectonics 8 V4 Driving Forces: Subduction Global Volcanism and Plate tectonics 9 V4 Driving Forces: Hot Spots Global Volcanism and Plate tectonics 10 V4 Driving Forces: Rifting Global Volcanism and Plate tectonics Ocean plates moving apart create new crust.
    [Show full text]
  • Largest Explosive Eruption in Historical Times in the Andes at A.D
    b- Largest explosive eruption in historical times in the Andes at A.D. Huaynaputina volcano, 1600, southern Peru Jean-Claude ThOuret* IRD and Instituto Geofisicodel PerÚ, Calle Calatrava 21 6. Urbanización Camino Real, La Molina, Lima 12, Perú Jasmine Davila Instituto Geofísico del Perú, Lima, Perú Jean-Philippe Eissen IRD Centre de Brest BP 70, 29280 Plouzane Cedex, France ABSTRACT lent [DREI volume. km': Table The The largest esplosive eruption (volcanic explosivity index of 6) in historical times in the 4.4-5.6 I). tephra is composed of -SO% pumice with rhyolitic Andes took place in 1600 at Huaynaputina volcano in southern Peru. According to chroni- A.D. glass, crystals (mostly amphibole and bio- cles, the eruption began on February 19 with a Plinian phase and lasted until March 6. Repeated 15% tite), and 5% xenoliths including hydrothermally tephra falls, pyroclastic flows, and surges devastated an area 70 x 40 kni? west of the vent and altered fragments from the volcanic and sedimen- affected all of southern Peru, and earthquakes shook the city of Arequipa 75 km away. Eight tnry bedrock, and a small amount of accessory lwa deposits, totaling 10.2-13.1 km3 in bulk volume, are attributed to this eruption: (1) a widespread, fragments. The erupted pumice is a white, , -S.1 kn3 pumice-fall deposit; (2) channeled ignimbrites (1.6-2 km3) with (3) ground-surge and medium-potassicdacite (average SiO, and ash-cloud-surge deposits; (4) widespread co-ignimbrite ash layers; (5) base-surge deposits; (6) 63.6% 1.85% hlgO) of the potassic calc-alkalic suite.
    [Show full text]
  • Remotely Assessing Tephra Fall Building Damage and Vulnerability: Kelud Volcano, Indonesia George T
    Williams et al. Journal of Applied Volcanology (2020) 9:10 https://doi.org/10.1186/s13617-020-00100-5 RESEARCH Open Access Remotely assessing tephra fall building damage and vulnerability: Kelud Volcano, Indonesia George T. Williams1,2* , Susanna F. Jenkins1,2, Sébastien Biass1, Haryo Edi Wibowo3,4 and Agung Harijoko3,4 Abstract Tephra from large explosive eruptions can cause damage to buildings over wide geographical areas, creating a variety of issues for post-eruption recovery. This means that evaluating the extent and nature of likely building damage from future eruptions is an important aspect of volcanic risk assessment. However, our ability to make accurate assessments is currently limited by poor characterisation of how buildings perform under varying tephra loads. This study presents a method to remotely assess building damage to increase the quantity of data available for developing new tephra fall building vulnerability models. Given the large number of damaged buildings and the high potential for loss in future eruptions, we use the Kelud 2014 eruption as a case study. A total of 1154 buildings affected by falls 1–10 cm thick were assessed, with 790 showing signs that they sustained damage in the time between pre- and post-eruption satellite image acquisitions. Only 27 of the buildings surveyed appear to have experienced severe roof or building collapse. Damage was more commonly characterised by collapse of roof overhangs and verandas or damage that required roof cladding replacement. To estimate tephra loads received by each building we used Tephra2 inversion and interpolation of hand-contoured isopachs on the same set of deposit measurements.
    [Show full text]
  • The Impacts of a Laki-Like Eruption on the Present Swedish Society
    http://www.diva-portal.org This is the published version of a paper published in Natural Hazards. Citation for the original published paper (version of record): Sonnek, K M., Martensson, T., Veiback, E., Tunved, P., Grahn, H. et al. (2017) The impacts of a Laki-like eruption on the present Swedish society. Natural Hazards, 88(3): 1565-1590 https://doi.org/10.1007/s11069-017-2933-0 Access to the published version may require subscription. N.B. When citing this work, cite the original published paper. Permanent link to this version: http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-142876 Nat Hazards (2017) 88:1565–1590 DOI 10.1007/s11069-017-2933-0 ORIGINAL PAPER The impacts of a Laki-like eruption on the present Swedish society 1 2 Karin Mossberg Sonnek • Tomas Ma˚rtensson • 1 3 4 Ester Veiba¨ck • Peter Tunved • Ha˚kan Grahn • 4 4 Pontus von Schoenberg • Niklas Bra¨nnstro¨m • Anders Bucht4,5 Received: 16 May 2016 / Accepted: 18 May 2017 / Published online: 31 May 2017 Ó The Author(s) 2017. This article is an open access publication Abstract In this study, we analyse and discuss the possible impacts on the Swedish society of a volcanic eruption on Iceland, emitting ash particles and large quantities of sulphur dioxide. A scenario was developed, based on the historical Laki eruption of 1783–1784, to describe the content of a potential sulphur fog over time in Sweden. Due to its high complexity and the many uncertainties in the underpinning scientific data, the scenario was developed using a cross-disciplinary approach incorporating experts from different scien- tific fields.
    [Show full text]
  • Potential Impacts from Tephra Fall to Electric Power Systems: a Review and Mitigation Strategies
    View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by UC Research Repository Bull Volcanol DOI 10.1007/s00445-012-0664-3 REVIEW ARTICLE Potential impacts from tephra fall to electric power systems: a review and mitigation strategies J. B. Wardman & T. M. Wilson & P. S. Bodger & J. W. Cole & C. Stewart Received: 9 May 2012 /Accepted: 20 September 2012 # Springer-Verlag Berlin Heidelberg 2012 Abstract Modern society is highly dependent on a reliable identified to avoid future unplanned interruptions. To ad- electricity supply. During explosive volcanic eruptions, dress this need, we have produced a fragility function that tephra contamination of power networks (systems) can com- quantifies the likelihood of insulator flashover at different promise the reliability of supply. Outages can have signifi- thicknesses of tephra. Finally, based on our review of case cant cascading impacts for other critical infrastructure studies, potential mitigation strategies are summarised. sectors and for society as a whole. This paper summarises Specifically, avoiding tephra-induced insulator flashover known impacts to power systems following tephra falls by cleaning key facilities such as generation sites and trans- since 1980. The main impacts are (1) supply outages from mission and distribution substations is of critical importance insulator flashover caused by tephra contamination, (2) dis- in maintaining the integrity of an electric power system. ruption of generation facilities, (3) controlled outages during tephra cleaning, (4) abrasion and corrosion of exposed Keywords Volcanic ash . Eruption . Electricity . equipment and (5) line (conductor) breakage due to tephra Generation . Transmission . Distribution . Substation loading. Of these impacts, insulator flashover is the most common disruption.
    [Show full text]
  • Volcanoes: the Ring of Fire in the Pacific Northwest
    Volcanoes: The Ring of Fire in the Pacific Northwest Timeframe Description 1 fifty minute class period In this lesson, students will learn about the geological processes Target Audience that create volcanoes, about specific volcanoes within the Ring of Fire (including classification, types of volcanoes, formation process, Grades 4th- 8th history and characteristics), and about how volcanoes are studied and why. For instance, students will learn about the most active Suggested Materials submarine volcano located 300 miles off the coast of Oregon — Axial • Volcanoe profile cards Seamount. This submarine volcano is home to the first underwater research station called the Cabled Axial Seamount Array, from which researchers stream data and track underwater eruptions via fiber optic cables. Students will learn that researchers also monitor Axial Seamount using research vessels and remote operated vehicles. Objectives Students will: • Synthesize and communicate scientific information about specific volcanoes to fellow students • Will learn about geological processes that form volcanoes on land and underwater • Will explore the different methods researchers employ to study volcanoes and related geological activity Essential Questions What are the different processes that create volcanoes and how/why do researchers study volcanic activity? How, if at all, do submarine volcanoes differ from volcanoes on land? Background Information A volcano occurs at a point where material from the inside of the Earth is escaping to the surface. Volcanoes Contact: usually occur along the fault lines that SMILE Program separate the tectonic plates that make [email protected] up the Earth's crust (the outermost http://smile.oregonstate.edu/ layer of the Earth). Typically (though not always), volcanoes occur at one of two types of fault lines.
    [Show full text]
  • Atmospheric and Environmental Effects of the 1783–1784 Laki Eruption: a Review and Reassessment
    JOURNAL OF GEOPHYSICAL RESEARCH, VOL. 108, NO. D1, 4011, doi:10.1029/2001JD002042, 2003 Atmospheric and environmental effects of the 1783–1784 Laki eruption: A review and reassessment Thorvaldur Thordarson1 and Stephen Self 2 Department of Geology and Geophysics, School of Ocean and Earth Sciences and Technology, University of Hawaii at Manoa, Honolulu, Hawaii, USA Received 27 December 2001; revised 5 April 2002; accepted 8 April 2002; published 8 January 2003. [1] The 1783–1784 Laki flood lava eruption in Iceland emitted 122 megatons (Mt) SO2 into the atmosphere and maintained a sulfuric aerosol veil that hung over the Northern Hemisphere for >5 months. The eruption columns extended to 9–13 km and released 95 Mt SO2 into the upper troposphere/lower stratosphere (i.e., the polar jet stream), enforcing a net eastward dispersion of the plumes which reacted with atmospheric moisture to produce 200 Mt of H2SO4 aerosols. Away from source, the Laki aerosols were delivered to the surface by subsiding air masses within anticyclones. We show that 175 Mt of H2SO4 aerosols were removed as acid precipitation and caused the extreme volcanic pollution (i.e., dry fog) that effected Europe and other regions in 1783. The remaining 25 Mt stayed aloft at tropopause level for >1 year. The summer of 1783 was characterizedby extreme and unusual weather, including an unusually hot July in western Europe, most likely caused by perseverance of southerly air currents. The following winter was one of the most severe winters on record in Europe and North America. In these regions, the annual mean surface cooling that followed the Laki eruption was about 1.3°C and lasted for 2–3 years.
    [Show full text]